1. Field of the Invention
The present invention relates to an image forming apparatus and a printing method of performing printing of original images which may have various sizes, and sorting of printed paper sheets.
2. Description of the Related Art
In recent years, an image forming apparatus (henceforth, referred to as a fusion machine) which has functions as respective devices, such as a printer, a copier, a facsimile device, and a scanner in a single housing, has come to be known. Such a fusion machine includes, for example, four types of applications (or application programs) corresponding to the printer, copier, facsimile device and scanner, respectively, and thus operates as a printer, a copier, a facsimile device, and a scanner, by appropriately applying these applications, while having relevant hardware resources such as a display part, a printing part, an image pick-up part, etc. in the single housing, used for actually executing these functions.
Moreover, such a fusion machine may further have functions of binding sheets of paper with staples on which original images are formed by the printing function of the machine, attaching a cover page thereto, or forming a punch hole therein, so as to appropriately group these sheets of paper.
Furthermore, such a fusion machine may sort these sheets of paper on which original images are formed upon ejecting them from the machine. The term ‘sorting’ means the following operation, for example. In case of preparing a plurality of copies for a set of pages, these pages are ejected from the machine after printing in an order such that each copy is separated from another copy, and, also, each copy has a predetermined order of pages. Specifically, for example, as shown in FIGS. 1A through 1D, in case three copies of original images of three sheets each are formed, these three copies are ejected from the machine in the predetermined order of pages in each copy.
Such an operation of grouping or sorting is a work which is in many cases executed for a single job. However, such a printing job may include various types or manners, i.e., a single side printing, double side printing, a mixed printing in that original images having different sizes are mixed, or so. However, in case where different types of originals are mixed in a single printing jog, for example, in case single-sided printed paper sheets and double-sided printed paper sheets are mixed in a set of originals from which a plurality of copies are formed, the above-mentioned grouping or sorting may not be applied thereto.